Magnetic sensors can be employed for detecting and measuring a magnetic field in various industrial and commercial applications such as, for example, automotive, medical, aerospace, industrial, and computer applications. In such applications, the magnetic sensor can be biased with a magnetic field and electrically excited, typically with a constant current source or a constant voltage source. Examples of magnetic sensors include sensing devices that utilize magnetic sensing elements such as, for example, Hall-effect sensing elements, semiconductor magnetoresistor (SMR) components, anisotropic magnetoresistor (AMR) components, giant magnetoresistor (GMR) components, and so forth.
The majority of Hall-effect based magnetic sensors possess extremely low magnetic field sensitivities at larger air gap operations, which results in poor sensor output signals. AMR and GMR magnetic sensors tend to be more expensive. Hence, it is believed that a solution to these problems involves the implementation of a passive and wireless magnetic sensor with a high magnetic field sensitivity at large air gap operations. In practice, however, it has been difficult to achieve all of these features simultaneously.